Thank you for your inquiry.
I am not aware of any published consensus or evidence-based guideline which deals with the question you have asked. In this situation my personal practice is to either reinitiate therapy beginning at the same initial dose used when starting the original treatment regimen (in other words, start over) or retest, and base the dosing on the new test results. In most instances, we do the former.
Thank you again for your inquiry and we hope this response is helpful to you.
Phil Lieberman, M.D.